NBER Working Papers and Publications

Economists disagree about the factors driving the substantial increase in residual wage inequality in the U.S. over the past few decades. We identify and estimate a general model of log wage residuals that incorporates: (i) changing returns to unobserved skills, (ii) a changing distribution of unobserved skills, and (iii) changing volatility in wages due to factors unrelated to skills. Using data from the PSID, we estimate that the returns to unobserved skills have declined by as much as 50% since the mid-1980s despite a sizable increase in residual inequality. Instead, the variance of skills rose over this period due to increasing variability in life cycle skill growth. Finally, we develop an assignment model of the labor market and show that both demand and supply factors contributed t...

The economic and social mobility of a generation may be largely determined by the time it enters school given early developing and persistent gaps in child achievement by family income and the importance of adolescent skill levels for educational attainment and lifetime earnings. After providing new evidence of important differences in early child investments by family income, we study four leading mechanisms thought to explain these gaps: an intergenerational correlation in ability, a consumption value of investment, information frictions, and credit constraints. In order to better determine which of these mechanisms influence family investments in children, we evaluate the extent to which these mechanisms also explain other important stylized facts related to the marginal returns on in...